Tylenol (acetaminophen) is one of the most commonly used painkillers. It is safe for kids, during pregnancy, and while breastfeeding. However, just because it is safe, doesn't mean that it Acetaminophen metabolism and factors affecting toxicity. GrepMed Acetaminophen, also known as Tylenol, is used to help with pain & to reduce fever. However, taking too much acetaminophen can be harmful to the liver which filters out toxins & Figure 1 from Acetaminophen toxicity and 5 oxoproline (pyroglutamic acid): a tale of two cycles, one an ATP depleting futile cycle and the other a useful cycle. Semantic Scholar